In general, a clothes treating apparatus having a drying function, such as a washer or dryer, is a device for receiving laundry in a drum in a state that washing is completed. The clothes treating apparatus terminates the dehydration process, and supplies hot air into the drum to evaporate moisture of the laundry, thereby drying the laundry.
For example, a dryer may include a drum rotatably provided within a cabinet to receive laundry, a drive motor configured to drive the drum, a blower fan configured to blow air into the drum, and a heating device configured to heat air brought into the drum. Furthermore, the heating device may use high-temperature electric resistance heat generated using an electric resistance, or combustion heat generated by combusting gas.
Air discharged from the drum contains the moisture of the laundry, and thus becomes high temperature and humid air. Dryers may be classified according to a method for processing the high temperature and humid air, and thus divided into a condensation (circulation) type dryer for condensing moisture contained in the high temperature and humid air by cooling the air below the dew point temperature through a condenser while being circulated without discharging the high temperature and humid air out of the dryer, and an exhaustion type dryer for directly discharging the high temperature and humid air having passed through the drum to the outside.
For the condensation type dryer, in order to condense air discharged from the drum, the process of cooling the air below the dew point temperature may be carried out to heat the air through the heating device prior to being supplied to the drum again. Here, the loss of heat energy contained in the air is generated while being cooled down during the condensation process, and an additional heater or the like is required to heat the air to a temperature required for drying.
For the exhaustion type dryer, the dryer discharges high temperature and humid air to the outside and receives outside air at normal temperature, thereby heating the air up to a required temperature level through the heating device. In particular, thermal energy transferred by the heating device is contained in high temperature air being discharged to the outside, but it is discharged and wasted to the outside, thereby reducing the thermal efficiency.
Accordingly, in recent years, clothes treating apparatuses for collecting energy required to generate hot air and energy being discharged to the outside without being used have been introduced to increase energy efficiency, and a clothes treating apparatus having a heat pump system has been introduced as an example of the clothes treating apparatus. The heat pump system may include two heat exchangers, a compressor and an expansion apparatus, and energy contained in the discharged hot air is reused in heating up air being supplied to the drum, thereby increasing energy efficiency.
Specifically, in the heat pump system, an evaporator is provided at the exhaust side, and a condenser at an inlet side of the drum, and thus thermal energy is transferred to refrigerant through the evaporator and then thermal energy contained in the refrigerant is transferred to air brought into the drum, thereby generating hot air using waste energy. Here, a heater for reheating air that has been heated up while passing through the evaporator may be additionally provided therein.